docs: def gen_trace_planes(self, ridx):
          """
          :yields: trace and rupture planes for the given rupture index
          """
          with h5py.File(self.source_file, "r") as hdf5:
              for idx in ridx:
                  trace = "{:s}/{:s}".format(self.idx_set["sec"], str(idx))
                  plane = hdf5[trace + "/RupturePlanes"][:].astype("float64")
                  yield trace, plane